Performance should be the same (same architecture and transistor count), but because of the smaller node used by Samsung, the A9 produced by them should a little cooler than the TSMC one.

Spotting which one is from TSMC or Samsung could be pretty difficult, since the temperature difference between chips could be less than 1-2 degrees.

Further investigation should be made with a X-ray microscope, the see the real differences between both manufacturers.